Blue Iguana Recovery Program

The Blue Iguana: Battle against Extinction

Jul 1st, 2002 | By | Category: Blues in the International Press

AJ Gutman, International Iguana Society
John Binns, International Reptile Conservation Foundation

Extinction, a terrifying word meaning “no longer existing,” usually occurs as a natural consequence of functional extinction, which is when a species is no longer able to sustain itself in the wild. In a document issued by Fred Burton, Director of the Blue Iguana Conservation Project for the National Trust for the Cayman Islands on June 22, 2002, only 10-25 Grand Cayman Blue Iguanas (Cyclura nubila lewisi) remain in the wild. The total number of these animals known to exist anywhere in the world is fewer than 120. This places the magnificent Blue Iguana in the frightening position of being the most critically endangered reptile on earth. The report estimates that, without intervention, the Blue Iguana will be functionally extinct within 5 years.

Unique to Grand Cayman, the Blue Iguana is a giant lizard which can grow to 152 centimeters in length and weigh as much as 9-10 kilograms. Its declining population figures are mirrored in the crises that face many of the other Rock Iguanas of the West Indies. Trailing closely behind the Blue Iguana, also battling functional extinction, are the Jamaican Iguana (Cyclura collei) and the Anegada Iguana (Cyclura pinguis), both with very small surviving populations and listed also as ?Critically Endangered? on the IUCN Red list. The remaining species of Cyclura, 16 in all, are ranked from ,”Critically Endangered,” to ,”Threatened”. The IUCN Red List is the world’s most comprehensive inventory of the global conservation status of plants and animals. It uses a set of criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. Seven categories are in the IUCN Red List system: Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, Near Threatened, and Least Concern. A species is listed as threatened if it falls in the Critically Endangered, Endangered or Vulnerable categories. Cyclura onchiopsis, the 17th species, is already extinct.

The demise of Rock Iguana populations began with the human colonization in the West Indies. Iguanas were a traditional food source, and in some areas they still are hunted today. Subsequent to colonization came development that methodically paved-over pristine habitat, slowly, but steadily reducing and then fragmenting iguana habitat and populations. During this period, the introduction of feral predators and ungulates created another catastrophic element that continues to plague all Rock Iguanas. Feral predators have a devastating impact on remaining iguana populations by destroying nests and preying on young iguanas, leaving few to survive long enough to reproduce. Goats and cattle compete with the iguanas for a limited food supply. Between habitat loss and introduced predators, the Blue Iguana, tragically, has suffered the greatest losses.

The Blue Iguana was first described to science in 1940 by Bernard C. Lewis, who noted in his paper that ,”the species is nearly extinct ,” [local] people say since 1925 the ,”guanas,”have become so scarce that it is no longer worth their while to hunt them.,” A survey conducted for the Cayman Islands Government in 1988 by Roger Avery recorded only three iguana sightings in two weeks of intensive searches. The National Trust for the Cayman Islands, long aware of the precarious status of the island’s endemic iguanas, established a captive breeding program in 1990 and has been producing a small number of animals for a number of years. The program began with two adults and was expanded to 6 adults and 20 juveniles the following year through the incorporation of illegal captives held on the island. However, though some progress has been made in breeding, little natural habitat remains in which to release them. Fossil evidence shows that C. n. lewisi was once distributed throughout Grand Cayman, but today only a miniscule 3.7 square kilometers of iguana habitat remain. Ongoing problems with nutrition also resulted in low fertility rates, and the iguana’s diet has had to be changed several times.

With three years of funding provided by Friends of the National Zoo in 1992, Project Director Fred Burton and intern Kevin Gould were able to conduct field research and estimated the wild population between 100 and 200 individuals. Genetic testing revealed the initial captive pair to be partial hybrids with the Little Cayman Brown Iguana (C. n. caymanensis) from neighboring Little Cayman and Cayman Brac, and they and their offspring had to be excluded from the breeding program. The Blue Iguana is currently classified as a subspecies of the Cuban Iguana (Cyclura nubila nubila); however, recent genetic studies indicate it may be distinct at the species level (see Malone & Powell in Iguana Times 9(1&2)).

In 1993, The World Wildlife Fund – UK sponsored a large display and breeding enclosure in Queen Elizabeth II Botanic Park. That same year, two sterilized male hybrids were released into the National Trust’s 625 acre Salina Reserve with internal temperature-sensitive radio tracking devices. The iguanas adapted quickly, established territories, and survived on the natural vegetation. However, all contact with them was eventually lost, and one was found bitten to death by a dog.

An adult pair was released in the same habitat patch in the following year. They were observed in the area for some time, until the female started test digging nest sites and contact was lost as they moved out of the protected area.

In 1995, eggs were collected from the first wild nest ever observed and incubated artificially; the land from which they were taken was being converted to cattle pasture. Temperature recordings taken from the empty nest were used to determine incubation temperatures at the newly constructed breeding facility in QE II Botanic Park. In 1996, two two-year-old captives were released in the Park and observed periodically throughout the year. Since none of the animals released in the Salina Reserve had survived, the decision was made to limit future releases to the Botanic Park.

From 1997-2000, additional captive-raised animals were added to the Park population and, by 2000, breeding in the wild was suspected but not confirmed until 2001.

The Grand Cayman Blue Iguana Species Recovery Plan

In November 2001, the World Conservation Union – Iguana Specialist Group (IUCN-ISG) produced the Grand Cayman Blue Iguana Species Recovery Plan detailing wide-ranging conservation measures. The stated purpose of the plan is to restore a wild population of the Grand Cayman Blue Iguana sufficient to remain viable in the long term. The plan is made up of a number of objectives, some of which have already been undertaken.

1. The most critical objective of the plan is to establish a protected area sufficient to support a wild population of 1,000 animals; the area will be formally managed and will be open to the public for nature tourism activities. To this end, the surveys of existing wild habitat and relict populations have already been conducted and produced the disturbing statistics that have served to increase the urgency of the remaining proposed conservation measures. International fundraising efforts are desperately needed to provide money for securing land and restoring habitat.

2. A part of the Blue Iguana’s former range on Barker’s Peninsula is to be restored and restocked. This area will be protected by the Cayman Island Government as a National Park.

3. Enhancements are to be made to the existing iguana habitat in Queen Elizabeth II Botanic Park. This includes a supportive feeding regime, the creation of additional nesting areas, and feral animal control measures.

4. Renovation and expansion of the existing breeding facility, improvements to nutrition and husbandry, as well as recruitment and training of new staff are necessary so that a sufficient number of animals will be available for reintroduction into portions of the Blue Iguana’s former range and for restocking the new preserve.

5. Through the American Zoo Association (AZA) Iguana Species Survival Plan (SSP) a genetically diverse captive population of 225 iguanas is to be established as a hedge against extinction in the wild.

6. The final objective is crucial: to secure sufficient financial, technical, and human resources to implement this action plan.

The Species Recovery Plan has many strengths as well as weaknesses. The Blue Iguana is a popular conservation symbol in the Cayman Islands and is legally protected (the Animals Law of 1976). A small breeding and headstarting facility already exists and the restocking of QE II Botanic Park is partially underway with some breeding also occurring in the wild. Field research on habitat restocking, diet, territorial ranges, and nesting ecology has been ongoing for 11 years. Detailed data from comparable studies of C. n. caymanensis on Little Cayman also are available.

International support for Cyclura conservation from zoos and conservation foundations already exists, but a deeper commitment, particularly from warm-climate southern zoos in the US is desperately needed. Disturbed habitats with the potential to be restored are available within existing protected areas. The Blue Iguana appears to be adaptable to such man-modified habitats and, with intensive management; these areas should be appropriate for restocking.

On the negative side, the eradication of introduced predators is very expensive, as is land acquisition and habitat conversion. The restocked population at QE II Botanic Park experiences a 60% nest failure rate and outstanding nutritional issues still exist. The facility is somewhat distant from schools and from most volunteers. Without a constant education effort, public interest and concern quickly fade.

Because the Blue Iguana has a high recognition factor, and its name has been used in movies and on hotels and restaurants in many places around the world, one would assume that all of that notoriety would assure the protection and long-range security of the species ? but this is far from reality. Many Grand Cayman residents are both surprised and shocked when they learn that their own endemic species, the famous Blue Iguana, is in serious trouble and headed for extinction. The fact that thousands of Green Iguanas, introduced from Honduras, run around on the western part of the island, only serves to confuse matters.

Field surveys and improvements to the breeding facility are already underway. The diet for animals at the breeding facility now incorporates ZooMed® pellets, thanks to a grant from the International Reptile Conservation Foundation. Raised beds have been planted to grow fruit and native plants. An area has been cleared to accommodate an expansion of breeding cages, and overgrown vegetation around existing cages has been cut back to afford more light penetration (the iguanas’ daytime activity periods had been shortened as a consequence of overshading). The Blue Iguana Fund, which has funded a large portion of efforts to conserve C. n. lewisi to date, is now exhausted, and further progress will depend on the acquisition of additional new sources of funding.

Your Help is urgently Needed

Despite the existence of the C. n. lewisi Recovery Plan for restoring viable populations of these animals for the long term, as well as the involvement of the scientific community and other organizations, funding for these efforts is far from secure. ?Funding? is often understood to imply that financial resources can be obtained through government and other institutions, whereas, in fact, a good portion of the financial resources needed for success of the Recovery Plan will rely on revenue generated from donations, sponsorships, merchandise sales, virtual adoptions, and other similar programs. The financial and human resources needed to develop these programs are also in limited supply, which, in turn, hampers making such promotions available to the public.

What can you do to help? First and foremost, the famous Blue Iguana is in serious trouble and needs the attention of the public in order to bring focus and financial assistance to the recovery effort. Depending on available resources, assistance could include building materials and the assistance of local Grand Cayman contractors and residents to aid in the construction of the expanded breeding facility. Financial donations and sponsorships are desperately needed to cover the diverse needs of recovery and stabilization of the species, assistance in advertising and promotion of the recovery plan through mass media distribution, and sponsoring of volunteers are all needed. All donations are tax deductible. Contact names are listed at the end of this article. is presently offering the special poster, “Got the Blues,” featuring art of the Blue Iguana, mouse pads, and Blue Iguana apparel. Profit from these sales goes directly to the Blue Iguana Recovery Program.

A special donation program offered allows you to have your name or company logo printed in the Official Blue Iguana Recovery Plan and your own hardcopy of the plan. The Recovery Plan details all of the steps in the program, the people involved, the proposed actions, and other pertinent data. This program provides an opportunity to add your name to this important document, signifying your support for a conservation program working to prevent the extinction of a magnificent creature called the Blue Iguana. Please check for details. Purchases (donations) can be made on-line.

Other programs such as a virtual adoption also are being developed. Such a program would allow you to name a Blue Iguana (for official use in all records) and receive a photograph of the iguana and other information about the animal that you adopt.

Support from the International Iguana Foundation

The International Iguana Foundation (IIF) is essentially the fund-raising branch of the IUCN- Iguana Specialist Group. It has been in operation since August 2001, when it was incorporated as a not-for-profit organization in the state of Texas.

The purpose of the IIF is to ensure the long-term survival of all iguana species through habitat protection, education, scientific research, and captive management. Funding comes through annual financial pledges from members and member organizations.

The IIF Board has already provided support for the Grand Cayman Blue Iguana Species Recovery Plan. But, given the sense of urgency engendered by the most recent population survey, the IIF is working to provide additional resources.

Survival of the species is focused on captive management efforts both on Grand Cayman and amongst the participating members of the American Zoo Association (AZA) Rock Iguana Species Survival Plan (SSP). The entire captive population will be managed as a single unit to optimize their genetic diversity. Guiding this process is Tandora Grant of the San Diego Zoo’s Centre for Reproduction of Endangered Species (CRES) along with the Small Population Management Advisory Group.

Contacts for the Blue Iguana Recovery Program

Fred Burton, Blue Iguana Conservation Project, Grand Cayman
Rick Hudson, Program Officer, International Iguana Foundation
John Binns,,International Reptile Conservation Foundation
AJ Gutman, International Iguana Society


Burton, F. 1996. Any Hope for Grand Cayman’s Blue Iguana? Iguana Times (Journal of the International Iguana Society) 5(4):75-79.
Dorge, R. 1996. A Tour of the Grand Cayman Blue Iguana (Cyclura nubila lewisi) Captive-breeding Facility. Reptiles 4(9):32-42.
Malone, C.L. and R. Powell. 2002. Comments on a phylogeny of iguanid lizards. Iguana Times (Journal of the International Iguana Society) 9:9-11.
IUCN/SSC Iguana Specialist Group 2001. The Grand Cayman Blue Iguana (Cyclura nubila lewisi) Species Recovery Plan 2001-2006. National Trust for the Cayman Islands, Grand Cayman.
IUCN web site

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